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By L. T. Loe, A. S. Norsk, Mo i. Rana

High production rate and good stability demand the optimization of all phases of electric pig iron smelting. This is important with respect to slag chemistry, which to a large extent regulates the process temperature in electric smelting. Controlled basicity and slag volume. and a satisfactory screen analysis of the reduction material and sinter, are of the utmost importance for smooth furnace operation. Large variations in slag volume and in B/ A and C/Fe ratio will have an influence on the furnace resistance and thus the specific energy development in the furnace, which lead to variable reduction of SiO.. The result will be variable hot -metal quality and un-stable furnace operation.

Jan 1, 1970

By D. E. Keeley

Introduction Gunite is a mixture of sand and cement applied to any surface by being shot by compressed air through a nozzle, where it is wetted just before leaving the orifice. The mixture is transported through a hose from a machine called a 'cement-gun'(l). Guniting of rock surfaces has been standard practice at the Mcintyre Porcupine Mines, Limited, for several years. Where used on walls and backs of cross-cuts; shaft stations, and other rock openings, as an air seal, gunite has eliminated the necessity of constant scaling to keep rock from falling from these places, and, under worse conditions, it has been used in place of timber supports. This has been of definite help in reducing costs, promoting safety, and minimizing fire hazards. During the past year guniting has been quite extensively used here in the rock head-works of the new internal shaft, No. 12, sunk from the 3,875-foot level. Gunite is at present being applied to the stations of that shaft well below a mile from the surface. This paper describes the method of guniting as carried out at the McIntyre, and illustrates how, by the adoption of this process, mining problems connected with scaling and loose ground have been completely solved. It is hoped that the information presented may stimulate discussion and assist in the use of gunite in this and other mines. The guniting method of applying cement was first developed by Carl E. Akeley (2), Curator of the Field Museum, Chicago, in 1907, and was exhibited in New York at the Cement Show in 1910. The museum was located in one of the old World's Fair buildings, built of roughcast and in bad repair. Mr. Akeley, who was a man of inventive nature, set about devising means of applying cement to repair the walls. The cement-gun was the result. Mr. Akeley was a taxidermist of note, a sculptor, and also the inventor of the Akeley camera. In his work, he was in the habit of using fast setting materials to build up foundations for statues, etc.

Jan 1, 1934

By P. Bramwell, R. Tremblay

"The Port Radium leaching plant of Eldorado Mining and Refining, Limited, produces 450 t./d. of sulphuric acid leach liquor containing l. 73 g. /I. U 308. After solvent extraction, the waste solution is discarded at 0.002 g./l. U30s for a recovery of 99.8 to 99.9 per cent. The solvent is acidified with weak sulphuric acid, loaded to 4.5 g./l. U80:1 in three-stage extraction, scrubbed with water, and stripped with soda-ash solution in single-stage stripping. Caustic removes the UaOs from the pregnant strip solution as a precipitate. The slurry is filtered, re-pulped with water, and re-filtered. The pressed precipitate at 81 to 82 per cent equivalent U30s is dried and packaged. The carbon-ate filtrate is cooled to remove sodium sulphate build-up and carbonated to convert excess caustic. Reagent consumptions are 4.1, 0.22, and 0.39 pounds per 1,000 gallons of pregnant solution for Diesel oil, amine, and alcohol, respectively. Caustic consumption averages 1.3 to 1.4 pounds per pound U3O8.Extraction and stripping is accomplished in sheet-iron mixer-settlers lined with Phenoline. Piping on both circuits is Schedule 80 polyvinyl chloride. Valves are straightway Buna N lined with American Hycar diaphagms. Extensive instrumentation ensures good metallurgy with a minimum of variations and labour. Mixing in a continuous organic medium and careful acidity control are required to minimize third-phase formations. Heating the precipitate slurry is conducive to good filtering in Perrin presses with neoprene-coated, rolled-steel sectors. Sodium sulphate is crystallized from carbonate filtrate solution by batchwise cooling to 54°F. with lake water."

Jan 1, 1959

By M. Saghaeian, R. Hejazi, Fakoor Sanat Tehran Company, H. Abedini, M. Zare

"Dewatering of final tailings is one the biggest issues in iron ore processing plants. Because of the fine and hydrophilic particles in the iron ore tailings, dewatering of such material is difficult and, in most of the cases, needs to be processed using expensive and complicated equipment. In this study, a novel method based on classification of small and large particles has been proposed to improve the dewatering performance of iron ore tailings. In the proposed method, a hydrocyclone has first been used to separate the fine and coarse fraction of iron ore tailings. Then, the coarse fraction (hydrocyclone underflow) is easily dewatered by using vacuum belt filter. Then, the fine fraction (hydrocyclone overflow) is primarily dewatered by using a high rate thickener. Finally, the thickener underflow is added to the bed of solids on the same belt filter, which is used for dewatering of hydrocyclone underflow. The efficiency of this method has been compared with other solutions for tailings dewatering including changing vacuum filtration parameters, using fabric with larger pore size, and using pressure filtration, all through laboratory scale experiments on the tailings of an iron ore processing plant in Iran. The results indicated the superiority of this method compared to the other ones, which increased the specific filtration capacity of the tailings by around 46%.INTRODUCTIONWet beneficiation of minerals requires a substantial amount of water to enhance the efficiency of the process. Used water should be recovered at the end of process to minimize shipping costs, meet contract specifications, and reuse process water (Wills and Napier-Munn, 2006). Dewatering equipment is usually divided into sedimentation (thickening) and filtration (pressure and vacuum) equipment, the choice of which depends on particle size, solid content of slurry, and material nature (Mular et al., 2002)."

Jan 1, 2016

By G. Macfarlane

"In 1985, a crushing plant, located in the feed preparation area of Kidd Creek's copper smelter, was modified. The plant, which originally had treated only copper-bearing materials for the smeller, at a rate of 10 tonnes per hour, was expanded to 40 tonnes per hour capacity and modified to treat silica ores to meet the smelter’s flux requirement and also gold ores from the company's Hoyle Pond property. In the storage area adjacent to the crushing plant a 300 tonne per day gold mill was constructed.This paper outlines the construction and first year of operation of the crushing plant and gold mill with emphasis placed on the capital and operating advantages to be gained by utilizing an existing metallurgical infrastructure.IntroductionThe Kidd Creek Mines Ltd. copper-zinc-silver orebody is located 24 km north of Timmins, in Northern Ontario . Mining of this massive sulphide de posit commenced in 1966 and, in the ensuing years, a concentrator and zinc plant were constructed at the metallurgical complex, approximately 17 km by rail from the mine site . At this same site, in 1981, a copper smelter and refinery were commissioned. The smelter which utilizes the Mitsubishi smelting process for the continuous production of blister copper from copper concentrate, has been comprehensively described in previous papers.At the time of the smelter construction, a small (10 tonnes per hour) crushing plant was installed in the smelter's feed preparation area. This plant was used to treat the copper-bearing revert material produced by the smelter, and, apart from periods when slags and matte were produced through furnace drainage at the end of each operating campaign, it was generally under-utilized. This fact, together with the requirement to devise a more cost effective method of providing silica flux for the smelting operation, was the basic rationale for modifying and expanding and crushing plan t. At the same time, development at Kidd's Hoyle Pond orebody had progressed to such a stage that a gold mill of 300 tonnes per day was warranted."

Jan 1, 1988

By Michael Harley, E. Guy Charleworth

"Bedding-parallel thrust-hosted gold veins are developed in the Sabie-Pilgrim's Rest goldfield, eastern Transvaal, South Africa. The reefs display a complex history characterized by temporally and spatially overlapping events of similar mineralization and deformation. Recognition of the episodic reactivation of these low angle (5° to 10°) thrust faults implicates high fluid pressures (equalling or exceeding lithostatic pressures). Geochemical constraints limit the amount of fluid-rock interaction and the occurrence of transgressive mineralization within the Archaean granitoid basement suggests that the high pressure fluids originated at depth beneath the Transvaal Basin.Similarities exist between gold deposits of Sabie-Pilgrim's Rest and Telfer, Western Australia as well as Passagem de Mariana, Minas Gerais, Brazil. All deposits are sub-parallel to the enclosing bedding which is shallowly inclined. Furthermore, they are also hosted by contractional deformational structures and are clearly epigenetic in origin."

Jan 1, 1994

By C. M. Díaz, P. J. Mackey, P. Coursol

In a recent paper [1], the present authors discussed calculated energy consumption numbers in copper sulphide concentrate smelting for four different smelting technologies. For the present study, from among these technologies, they selected the Noranda/Teniente continuous bath smelting followed by Peirce Smith (PS) converting route to investigate the impact on total energy requirement of some key process variations, such as tuyere injection of dry concentrate vs. slingering of wet concentrate over the molten bath, continuous converting vs. conventional batch PS converting and commercially proven slag cleaning alternatives. In their calculations, the authors used the same thermochemical model and methodology used in their earlier paper. This approach to explore plant design options provides an interesting basis for evaluating flowsheet modifications that could lead to significant copper smelting energy savings. The METSIM software was used in the present paper to carry out heat and mass balance computations for 8 different flowsheet configurations. The results are presented and discussed in the paper with respect to copper recoveries, energy requirements and CO2 emissions.

Jan 1, 2011

By R. A. Crouse

The Tanco pegmatite at Bernie Lake, in the Lac du Bonnet mining district of southeastern Manitoba, is a unique deposit of Li, Rb, Cs and Ta, with substantial reserves of Be and several industrial minerals. This paper summarizes the present state of understanding the regional geology, structural setting, zoning, mineralogy and geochemistry of the pegmatite, and the mining and ore-processing methods used in its exploitation.

Jan 1, 1979

By W. H. S. McFarland

THE Yukon Consolidated Gold Corporation, Limited, a Canadian company, operates alluvial gold dredges in the Klondike goldfields of Yukon Territory. Its operations are of unique interest to Canadian mining as it is the only large-scale placer mining operation of this type in Canada. Its properties lie in the valley of the Klondike river and its tributaries, Bonanza, Hunker, Bear, Last Chance, and All Gold creeks, and in the valley of Indian river and its tributaries, Dominion, Gold Run, Sulphur, Eureka, Montana, and Quartz creeks. At the end of 1938, they consisted of 1,650 placer mining claims and 9 leases or concessions. They cover a belt with an area of approximately 1,000 square miles. This vast area covers in part claims which have been previously worked by other methods such as 'drift' and 'open-cut' mining, and areas which were too low grade for such methods. The ground held by the Company is not held in freehold but in the form of mining claims and mining leases granted by the Dominion Government under the provisions of the Yukon Placer Mining Act. Full-size creek claims are 500 feet in length by 1,000 feet on either side of the base-line. Hill and bench claims are 500 feet up and clown the valley and 1,000 feet at right angles to the valley. All claims are held on the basis of an annual renewal fee of $10 for each claim plus 'representation work' of an assessed value of $200 per claim per annum. For the purpose of such representation work, claims may be 'grouped'. This means that work done by one dredge is sufficient to 'represent' a comparatively large block of claims. It is only in this way that it becomes possible to consider operations on a large scale over a term of years, for such operations would obviously be impossible on law-grade ground if representation work had to be done separately on each individual claim in each year.

Jan 1, 1939

By Xiang Li, Xibing Li

It is paramount that the stability of rock slopes be correctly accounted for under diverse operating and environmental conditions. Owing to different sources of uncertainty entailed in such stability problems, conventional deterministic approach through the calculation of a factor of safety (FOS) cannot reflect quantified uncertainties explicitly and sufficiently. Thus it is highly desirable to invoke the reliability approach to consider uncertainties in a systematic manner. Nowadays, the current design standards have an increasing tendency to ensure rock slope stability by pre-defining a target reliability index (or target probability of failure), viz., the reliability level of a rock slope is pre-set as a target to be satisfied. In such a situation and considering the fact that the FOS used as an indicator of slope performance still has a very wide acceptance, we focus on proposing an inverse-reliability-based methodology which aims at developing a two-fold indicator strategy, i.e., using the FOS and reliability together to deal with slope stability problems. The basic idea behind it is to utilize a so-called inverse first-order reliability method (IFORM) to directly calibrate the FOS provided the target reliability index has been given. In this way, the calibration scheme relating the FOS can be rationally done by not only incorporating uncertainties, but also satisfying a desired level of the prescribed reliability. Based on this, to make the IFORM computationally feasible and also reduce its computational cost, we introduce the response surface method (RSM) to generate a surrogate for the FOS-based limit state function (LSF), considering the lengthy and complicated form of the FOS in some recognized methods (e.g., within the framework of limit equilibrium). Distinguished from the existing RSMs that potential inadequacies may arise, we present an RSM based on a hybrid approach combining support vector machine (SVM; used as a regression technique) and uniform design (UD; pertaining to experimental design). Using a representative example of rock slope stability problem, we demonstrate the feasibility and validity of the developed methodology, during which the associated sensitivity study and further discussion are also performed. By dint of such a methodology, we can establish a link between the conventional deterministic approach and the reliability approach, where a logical and realistic framework is provided, for cases achieving the specified reliability, to assist in selecting the FOS which remains adequate for rock slope stability even in the face of uncertainty.

Jan 1, 2015

By Ralph H. Cleland

Introduction The mines of northern Ontario have entered the class of deep mines. It has often been asked: How deep can operations be carried on? What will the temperature be? This paper is a résumé of a brief survey of rock temperatures made by the Ontario Department of Mines during the year 1932. Present temperatures were recorded and the geothermal gradients that now exist were determined. No alarming situations were found, but many interesting ones have been noted. Northern Ontario mines are fortunately situated as compared with most deep-level mines of the world. The mean yearly temperature, as determined from meteorological records of the Federal Department of Marine, is from 33 to 38 degrees Fahrenheit. The tables on the next page show the temperature range in and about our mining camps ( l ). As no exact figures were obtainable for Kirkland Lake, the data for Iroquois Falls, which is about 50 miles northwest, were taken as applicable there. The figures for Timmins were checked against those of Cochrane and Iroquois Falls and found to be very similar, so that the Cochrane data may be used for the Porcupine camp. The yearly mean temperature is considered to be 33.5 F.

Jan 1, 1933

By J. Tuominen

Outokumpu Direct-to-Blister Flash Smelting is currently in operation in two smelters, a third one is under construction and a fourth one is in the design phase. The two smelters in operation are the Glogow 2 smelter of KGHM Polska Miedz S.A. in Poland and the Olympic Dam smelter of BHP Billiton in Australia. The Outokumpu Direct-to-Blister smelter of Konkola Copper Mines Plc. in Zambia is under construction and the new smelter of Glogow 1 is under design and waiting for final go-ahead decision. Additionally, the Garfield smelter of Kennecott Utah Copper Corp. makes blister copper out of matte in a Flash Converting furnace. A similar operation is under construction for Y anggu Xiangguang Copper Co. in China. The slag cleaning process, which is needed to clean the slag of the Direct-to-Blister Flash Smelting Furnace, has different requirements depending on the feed to the flash furnace. These differences are discussed in the paper. The differences between the processes and slag produced are discussed as well as the metallurgical requirements for slag cleaning. The Direct-to-Blister process, where the blister copper is produced directly from concentrate in one step, requires at least a partial treatment of the slag in an electric slag cleaning furnace. The existing impurities determine the specific requirements of the actual cleaning process. The different processes are discussed in the paper. The newest developments of Outokumpu Technology Oy for electric slag cleaning furnace design are presented as well as the characteristics which the furnace shape gives to the process.

Jan 1, 2007

By A. L. Nunes, J. R. E. Garcia, G. Silva, U. Prasad, C. Rabe

"Drilling through the Guayabal shales, a gray calcareous shale, and the C1 to C100 formations, a well-cemented calcareous-sandstone in Corralillo field, Mexico, is a challenge due to severe wellbore instability problems. Additionally, there has been a history of ineffective reservoir stimulations by hydraulic fracturing. To predict and mitigate these subsurface issues, it is essential to characterize the mechanical properties and rocks strength for a better prediction of borehole stresses and collapse pressure during drilling. Various correlations can be used to estimate and/or determine the unconfined compressive strength but most of them are based on transit time and porosity.In this study, grain size distribution was combined with acoustic travel time, porosity and static Young’s modulus to develop a rock strength prediction model for the turbiditic sandstones of the Chicontepec basin. The main reason this combination of parameters was employed was because of the wide variations in rock strength estimated using traditional porosity-based correlations such as the McNally’s (1987), GMI-Jizba-E’s and Bradford’s (Bradford et al., 1987).To develop a new correlation, a geomechanical and microstructural campaign was initiated. Mineralogy by X-ray diffraction, pore and grain sizes by petrography, clay distribution by SEM and porosity by mercury intrusion porosimetry were measured. Static and dynamic Young’s moduli and Poisson’s ratios were acquired by triaxial and ultrasonic measurements on undisturbed sandstone samples from the Chicontepec basin. More than ten offset wells with wireline data, including transit time, porosity, density, resistivity and gamma ray, were used for reservoir and geomechanical characterizations.Our analyses lead us to propose a new correlation for predicting the uniaxial compressive strength (UCS) of sandstones of the Chicontepec Basin as a function of transit time and grain diameter, both of which can be derived independently from destructive laboratory tests. Our results also highlight the importance and value adding of a combined approach incorporating grain size analysis in the rock strength prediction. The UCS predicted using the transit-time and grain-size-based model presents a median value (P50) of 76 MPa, P10 of 55 MPa and P90 of 89 MPa."

Jan 1, 2015

By David R. Lentz

Abstract -At True Hill in southwestern New Brunswick, low-grade porphyry-style Bi-Sn-Mo greisen mineralization is associated with the cupola of an epizonal granite porphyry (granite) that also exhibits three episodes of brecciation. The first episode of brecciation is an in situ, 8 m to 10 m wide transitional zone of net-veined to coarse-grained "blocky" endogranitic mesobreccia that is chloritized and greisenized and hosts weak disseminated mineralization. ln a zone doser to the host rock­ granite contact, angular fine- to coarse-grained endogranitic mesobreccia with greisenized matrix is superimposed on the earlier transitional breccia. The latest episode is fault-controlled and consists of quartz- and chalcedony-hosted subangular to rounded fine-grained "pebble" mesobreccias that crosscut and brecciate the other breccia types, as well as the adjacent altered metasedimentary country rocks. The first two episodes of brecciation are magrnatic-hydrothermal in origin related to hydrofracturing of the granite carapace and are accompanied by greisenization and mineralization, whereas the post-mineralization, silica-hosted, "pebble" mesobreccias related to hydromagrnatic, low­ temperature fluid circulation and/or boiling along faults near the contact. These magmatic­ hydrothermal and hydromagmatic mesobreccias are similar to those associated with W-Mo-Bi porphyry-greisen mineralization at the Mount Pleasant deposit.

Jan 1, 1994

By J. Chenier, M. Boissoneault, D. Ducharme, R. Schonewille

The operation of Falconbridge's Sudbury nickel smelter has undergone significant change since the production was consolidated to a single electric furnace in 1994. In the late 1990's a capital program of about $100 MM (Cdn) was undertaken to expand and modernize the smelter. This project, known as Smelter 2000, was mainly driven by the need to process the new concentrate produced at Falconbridge's Raglan operation in northern Quebec. Included in the scope of the project was the installation of dry concentrate handling facilities, modifications to the roaster feed preparation system, installation of a matte granulation system and modification of one of the converters. Improvements to in-plant hygiene were also an important part of the Smelter 2000 project. Over the past 5 years much has been learned about the challenges in treating two significantly different concentrates. More recently, the introduction of a third concentrate from Falconbridge's new Montcalm operation near Timmins, Ontario has added another dimension to the operation. This paper will describe how the main challenges from the past 7 years have been overcome and discuss the path forward for the Sudbury Smelter Business Unit.

Jan 1, 2005

By D. Duffy, V. Papangelakis

"MgCl2 brines present a number of potential advantages for the processing of saprolite ores for nickel production. With a chloride system it is economically requisite to recover hydrochloric acid, which can be performed in a more energy efficient manner by precipitation and subsequent decomposition, as compared with conventional pyrohydrolysis. In addition, concentrated MgCl2 solutions enhance the activity of acid used, allow atmospheric leaching at elevated temperature and inhibit magnesium dissolution, which reduces acid consumption and increases metal selectivity. Leaching and iron control experiments have been conducted in concentrated MgCl2 brines, up to 4.5 m, to determine the most amenable process conditions. INTRODUCTIONChloride metallurgy has received an increasing amount of attention in recent years, especially with respect to the treatment of nickel laterites. Although the limonitic fraction can sometimes be economically treated by High Pressure Acid Leaching (HPAL), acid-consumption problems are encountered with the higher magnesium content of the saprolite fraction. As magnesium does not hydrolyze under HPAL conditions, as iron and aluminum do, any sulphuric acid used to leach magnesium is subsequently neutralized and wasted. In addition, this magnesium must later be disposed of in some fashion, further complicating the process. The most common method used to process saprolite is the Rotary Kiln-Electric Furnace (RKEF). This uses a kiln to dry and preferentially reduce nickel, before sending the calcine to an electric furnace. Although nickel recoveries are high, and the problems of acid consumption are avoided, the capital and energy costs associated with this process are high (de Bakker, 2011).The problems outlined above have led to the investigation of an atmospheric chloride process for the treatment of saprolite ores. The use of a chloride system presents a number of advantages, but also a few limitations. Metal chlorides tend to be very soluble, with a few notable exceptions (silver, mercury and lead), allowing for smaller processing equipment through more concentrated solutions. This solubility also serves to reduce the potential for scale formation. In addition, a hydrochloric acid leach is more aggressive than a comparable sulphuric acid system, and the activity of the hydrogen ion can be augmented by further chloride addition (Peek, 2011). This activity augmentation in concentrated chloride systems, first reported by Jansz, has repeatedly been referenced as a motivating factor behind chloride hydrometallurgy (Jansz, 1983; Harris and Magee, 2003; Harris et al., 2004; Demopoulos et al., 2008; McDonald and Whittington, 2008; Demopoulos, 2011; Peek, 2011; Verhulst and Lakshmanan, 2011). This activity increase allows a similar amount of acid to perform more in a concentrated solution than in a dilute solution, decreasing overall acid requirements. As such, much focus has been placed on leaching in concentrated chloride systems, or brines, using calcium, magnesium or sodium as the cation (McDonald and Whittington, 2008)."

Jan 1, 2012

By L. Chunpongtong

One of the challenges of mine planning is to determine the most cost-effective replacement time for aging equipment. The lifespan of equipment, such as haul trucks and shovels, deployed in mining operations varies due to the nature of the material and ground conditions in which it operates. For engineering economists dealing with aging equipment, the options become an economic trade-off between higher maintenance cost versus the cost of new equipment. The discount rate plays a significant role in this decision; the higher the rate, the longer the economically optimal lifespan. Therefore, the ultimate question is: ?How can the relationship between the discount rate and the economically optimal lifespan be expressed mathematically??

Aug 1, 2013

By Joël P. T. Kapusta

Back in 1995, Air Liquide and Union Minière presented a joint paper at the Copper 95 – Cobre 95 Conference in Santiago, Chile, describing the first full scale plant trials of shrouded sonic injection in a Hoboken converter at the Hoboken smelter in Belgium. Almost a quarter of a century later, the technology known as ALSI, or Air Liquide Shrouded Injection, has been tested or commercially implemented in several copper and nickel smelters. Despite these successes, the copper industry did not adopt it widely in the same manner the steel industry adopted the Savard-Lee tuyere in the 1970s and beyond, not even in the way the lead industry adopted it with the Queneau-Schuhmann-Lurgi, or QSL, process. The development and implementation of bottom-blowing smelting and converting technologies in China in the last ten years, however, changed the industry’s perception that high- and ultra-high oxygen injection in copper smelting and converting was indeed possible under specific process conditions. In this paper, I retrace the key learnings of my journey with sonic injection over the twenty five years from my humble beginnings in my early years with Air Liquide, through plant trials and technology implementation in the late 1990s and into the first decade of the new millennium, and ultimately, to the most conclusive proof that the sonic injection design methodology I established is valid, and the calculation tools I developed are accurate. I conclude by sharing my thoughts about whether the deployment of the Savard and Lee legacy within the nonferrous industry was just a pipe dream or whether it will become a reality. INTRODUCTION In the context of lower quality ores and changing economic markets, copper smelters need to continuously innovate and improve to remain competitive and respect their corporate social responsibility engagements. One avenue towards this business, social, and environmental goal is to increase process intensity while lowering fossil fuel consumption to lower greenhouse gas emissions and reducing process off-gas volumes to better capture As and SO2–laden emissions. I believe high oxygen sonic injection for submerged tuyere copper bath smelting and converting is one technology that can help smelters achieve that goal of higher business, social, and environmental performance. Twenty five years ago, when I discovered that the Savard-Lee tuyere had revolutionized the steel industry (Savard & Lee, 1966; Knuppel, Brotzmann, Fassbieder, Savard, & Lee, 1972), I had a dream — or was it a vision? — that within the first decade of the new millennium, modern copper smelters operating submerged tuyere bath smelting and converting vessels will have implemented high oxygen sonic injection and will be reaping the financial and environmental benefits that the steel industry enjoyed in the 1970s. As we approach the end of the second decade of the new millennium, I have to admit that my dream has been all but shattered as the majority of copper bath smelting and converting vessels today continue to operate under bubbling regime conditions. This mode of operation is archaic, still requires tuyere punching and blows at inherently low enrichment levels, particularly in converting, producing large volumes of process off-gases. Under such operating conditions, regulations and emission quotas for As, SO2, and particulate matter oblige smelters to use not just primary or secondary hoods, but sometimes even tertiary hoods. I vividly recall being told, fifteen or twenty years ago when visiting smelters to promote the application of the Savard-Lee tuyere in nonferrous processes, that implementing sonic injection was not economically viable due to the high cost of compressing air and oxygen. Some of the smelters I visited back then have since mandated their engineering partners to design and build secondary or even tertiary hoods. I cannot fathom how secondary and particularly tertiary hoods, with all of their auxiliary equipment and added ducting, could be more economically viable than purchasing and installing a few compressors, expanding the pipeline network for compressed air and oxygen, and installing a new control valve train to feed sonic tuyeres. Besides, adding hoods does not address the problem of As and SO2-laden fugitive emissions at its source but merely provides a costly mitigation for it by capturing larger volumes of process off-gases rather than reducing these large volumes in the first place. Moreover, hooding does not reduce energy consumption nor does it increase process intensity, two aspects that I believe are critical for smelters to remain competitive and sustainable in a deeply changing market environment.

Jan 1, 2019

By David L. Anderson

"The government o f Canada has, since 1981, been under intense political pressure to modify its foreign direct investment (FOI) regulatory regime(1). To date the government's response has been limited to administrative and ""cosmetic"" changes: substantive issues have been largely ignored(2). However, as long as the economy continues to flounder , the Foreign Investment Review Agency (FIRA), as it is presently formulated , will continue to be an easy target for government critics . This phenomenon, in conjunction with the virtual certainty of a federal general election within two years, suggests that changes to the FIR Act will be seriously entertained by the present government.Recent events indicate that if change s are made, they will likely entail the adoption of a special-sector approach within the existing framework of a general screening system(3). Since this approach is currently employed in Australia(4), it would seem to be appropriate, from a public policy perspective to study that country's experience in developing and operating such a scheme. In doing so, I shall focus on the mineral sector; the rationale for doing so is as follows. First, this sector served as the focal point of the Australian FOI regulatory debater(5), Second , with the exception of the oil and gas industries, the non-petroleum mineral sector is one of the few areas of the Canadian economy wherein the Trudeau government has adopted an explicit domestic ownership target(6). Third, the non-petroleum mineral sector is, undoubtedly, a prime candidate to be denoted a s a special-sector if such a framework were to be utilized by the Canadian government!"".Although international comparisons are fraught with danger , a Canadian/Australian comparison is particularly appropriate(8). Both countries have reasonably similar economic, political and social structures . Furthermore, as noted above , Australia is the only other western country which employs a general screening mechanism for FOI. In addition, it utilizes a special area approach ; within this scheme, an explicit target of a minimum of 50% Australian ownership of all new resource projects has been formulated and clearly promulgated to all of the relevant interest groups. This policy, broadly defined, has been in place for more than six years and during this time the Australian mineral sector has, by world standards, prospered(9). Hence, the Australian experience in designating the mineral sector as a key area within a general screening system, should be of interest to Canadian policy-makers."

Jan 1, 1984

By T. Bhambhani, Mukund Vasudevan, Partha Patra, D. R. Nagaraj, P. Somasundaram

Selective Ni separation from ultramafic ores rich in serpentines has been a huge challenge in the mineral processing industry, and therefore highly inefficient. Analysis of the root causes of the challenges and consequent development of robust processing solutions were the main goals of the Cytec-Columbia. University-Vale Joint Development Program. In this context, the subject of this paper is limited to one of the key findings of this research program which is the influence of fibrous serpentines on grade-recovery characteristics. Specifically, the poor flotation behavior is characterized by an atypical reverse C-shaped grade-recovery curve.

Jan 1, 2011